#!/bin/bash

read -p "please input you grade:" u_grade
if [ -z $u_grade ];then
	echo "can't empty"
	exit
elif (( $u_grade>=90 && $u_grade <=100 ));then
	echo "good job,may be you can try join alibaba" 
elif (( $u_grade>=80 && $u_grade <=89 ));then
	echo "nice,may be you can try join tencent"
elif (( $u_grade>=60 && $u_grade <=79 ));then
	echo "come on,baby!may be you can try join facebook"
elif (( $u_grade>=0 && $u_grade <=59 ));then
	echo "keep on fighting,may be you can try join google"
else 
	echo "you must input [o-100] number"

fi
